9 Dehydration of Meat The dehydration of meat and poultry in granule form for soup ingredients is dealt with in this chapter, as being of more practical importance than the drying of meat in larger cuts, such as slabs, dice, etc which can only be dehydrated by the AFD method. Outlets for the latter products are relatively limited in Europe, whereas there is a worldwide market for soup-making materials. Meat granules and powders can be air dried or freeze-vacuum dried. The latter system has the undoubted advantage of quick rehydration, which is beneficial for soup mixes but, as previously stated, it is an expensive system and, therefore, the air dried product still finds wide acceptance in what is a very competitive market. It is on this system that the following processes are based. The dehydrator will require to have a completely separate plant for the handling of meat and poultry, as this cannot be carried out hygienically alongside vegetable processing. Ideally, the premises should be separate as well or, at least, properly subdivided if the two activities are carried on under the same roof. Otherwise, the required standard of hygiene cannot possibly be maintained. The local Health Authority should always be consulted before setting up a meat plant of any description, as there will inevitably be several by-laws in this context, which will have to be observed. It is also essential to have adequate cold storage in the factory, both for short and long term storage of raw materials. Where the latter have to be bought in at special times of the year, in order to gain a seasonal purchasing price advantage, low temperature storage (-29°C) will also be a necessity. 213 RAW MATERIALS Beef and mutton should be brought into the factory boned out and ready for processing, either frozen or fresh, as available. Oxtails, kidneys and other offal are usually bought frozen and held in cold storage until required. Poultry is bought plucked and eviscerated, either prefrozen or fresh, according to availability. The preparation of meat and poultry for processing, ie, the boning out of quarters, and the plucking and eviscerating of birds, is specialist work better carried on outside the dehydration factory, and there is little or no good reason for the dehydrator to tackle this, or involve himself with the additional equipment and labour concerned with this part of the work. A strict procurement specification for meat products should be set out, and there should be no difficulty in having this complied with by the suppliers as to fat content, trimming and quality generally, if reliable sources are contacted. CHICKEN GRANULES The poultry is thoroughly defrosted and the carcasses cleaned and prepared for the precooking. Well fleshed hens with a good flesh to bone ratio are the best for this purpose. Cooking Stainless steel jacketed vertical autoclaves, with perforated metal baskets, which lock on to a central spindle, are loaded with the chickens, and steam is applied to the outer jacket at 5.5atm. A small quantity of water is required in the bottom of the autoclave to start the cooking process, and the internal pressure of the vessel is brought up to 1 .2atm, after first venting the air. The chickens are cooked for 30-35min, or until such time as the flesh falls freely from the bones. The condensate and juices are drained off from the bottom of the autoclave, at the end of the cook, into a lower tank, where the fat and bouillon are separated. The fat is recovered, rendered and hardened for subsequent use as an ingredient in chicken soup. The bouillon is transferred to a stainless steam jacketed boiling pan and concentrated until 75 percent of the excess water has been removed. This is held for subsequent addition to the flesh. This concentration may alternatively be carried out in a vacuum pan. Fleshing The chickens then pass to a fleshing table where the operators remove the cooked flesh from the bone, transferring it to sterilised trays. 2 I4 Mixing The flesh, which must be scrupulously examined for small bones and gristle before leaving the fleshing tables, is then transferred to a steam jacketed mixer, and the bouillon from the batch of chickens just cooked is added back in its condensed form. The mixer is fitted with a ribbon-type blade, which rotates very slowly, thoroughly mixing all the flesh. The heat in the mixer jacket and the retention time are judged to reduce the bulk 15 percent by evaporation. If permitted by the specification, salt may be added at this point in the process. Mincing The meat is taken from the mixer-dryer and minced through a 2.4mm, 4.8mm or 9.5mm plate, according to the size of granule required. Drying With a small scale operation, drying is usually carried out in a stove dryer by the simple hot air convection method, although medium sized conveyor band dryers can be used equally well. Where a stove dryer is used, the meat is spread 25mm deep on previously sterilised trays, and the latter are racked on trolleys of a suitable size to fit the stove dryer. As a preliminary to drying on trays, however, where considerable handling of the meat has taken place, it is necessary to sterilise it, and one method of effecting this is to move each trolley, with the trays racked in position, into an autoclave of rectangular shape - similar to those used in the canning industry. Here, the product is sterilised with live steam at latm for about 20min. This is a necessary precaution to reduce the bacteriological count arising from handling, exposure to room temperature and general conditions which encourage bacterial growth. When using a conveyor band dryer, where no tray loading or predrying delays are involved, sterilisation may be omitted. In this case the meat granules are transferred directly on to the band dryer plates at a 7.5cm bed depth. Drying temperature is 66°C at the inlet, and the time of travel through the heat zones is 30-40min. From the dryer, the product passes through a cooling section, which reduces its temperature to 23°C. A suitable size of through conveyor dryer for this purpose would be 9m long and 1.5m wide, with a 3m cooling section. This would handle up to a ton of raw material an hour. Final moisture content should be 5 percent and the free fat content 35-40 percent. 215 Packing Hermetically sealed 4gal. tins, nitrogen-flushed, are almost invariably used for this and all meat packs. Ratio With well fleshed hens, this should be 3.5:l to 4:l. BEEF, MUTTON, HAM, OXTAILS, KIDNEYS The process for these meat products follows that for poultry very closely, in principle. For beef products, cow and bull beef is the best material to use for dehydration. Beef loins are a suitable cut, having relatively little fat. Oxtails must be defatted after cooking, and these will normally require precooking for 45-60min at 1.4atm in the autoclave to tenderise them sufficiently to allow removal of flesh from the bone. If difficulty is experienced in defatting, it is usually an indication that insufficient heat has been applied in the precook, and this must be controlled to obtain the best results on the fleshing and defatting tables. Well trimmed tails should be insisted upon in the procurement contract, as there is no recovery value in a large percentage of fat. Drying techniques are the same as for poultry, and similar drying temperatures are applied. Ratio 71 may be expected from lean tails. TYPICAL BUYER'S SPECIFICATION - USA CHUNK STYLE DEHYDRATED COOKED CHICKEN Description: Chunk style dehydrated cooked chicken, produced from fresh or frozen poultry. It is free of extraneous parts, such as hearts, gizzards, livers, kidneys, cartilage and bone. Ingredients: Cooked chicken, salt, MSG and anti-oxidant. Specifications: Physical and Chemical: Moisture 5% Maximum Fat 35% Maximum Salt 3% Maximum MSG 2% Maximum Protein 55% Minimum PH Anti-oxidant 10.0 millequivalents maximum per kilo of fat Less than 0.02% of the fat portion as BHA and 216 Propyl Gallate. Other anti-oxidants may be used to meet customer requirements or foreign Government Regulations Colour Golden brown Particle size Standard 1/4in. may be adjusted to meet customer requirements Flavour/Aroma Characteristic of cooked chicken Microbiological: Standard Plate Count Coliform, Yeast and Mould Negative in log tested Salmonella Less than 10,000 organisms per gram Negative by approved testing procedures General Requirements: The product conforms to all current USDA Regulations Governing the Inspection of Poultry and Poultry Products. TYPICAL BUYER’S SPECIFICATION-USA. CHUNK STYLE DEHYDRATED COOKED BEEF TYPE 1 Description: Chunk style dehydrated cooked beef, prepared from fresh and/or frozen beef. Ingredients: Cooked beef, beef broth, salt and MSG Specifications: Physical and Chemical: Moisture 5% Maximum Fat 35% Maximum Salt 4% Maximum MSG 3% Maximum Protein 50% Minimum Colour Flavour/Aroma Characteristic of cooked beef Particle size Microbiological: 5 millequivalents per kilo of fat Medium brown Standard 1/4in. may be adjusted to meet customer requirements. PH Standard Plate Count Coliform, Yeast and Mould Negative in log tested Salmonella Less than 10,000 organisms per gram Negative by approved testing procedures 217 General Requirements: The product conforms to all current USDA Regulations Governing Meat Inspection. TYPICAL BUYER’S SPECIFICATION - USA. CHUNK STYLE DEHYDRATED COOKED HAM Ingredients Cooked ham. Normal curing ingredients: Sodium Nitrite, Sodium Nitrate, Sodium Erythorbate, salt, MSG, Disodium 5- Inosinate, Disodium 5- Guanylate, smoke flavour and anti-oxidant. Specifications: Physical and Chemical: Moisture 5% Maximum Fat 35% Maximum Protein 50% Minimum Salt 6% Maximum MSG 2% Maximum Colour Pinkish Flavour/Aroma Characteristic of smoked ham Particle size Anti-oxidant Standard 1 /4in. may be adjusted to meet customer requirements Less than 0.02% of the fat portion as BHA and Propyl Gallate. Other anti-oxidants may be used to meet customer requirements or foreign Government Regulations Microbiological: Standard Plate Count Coliform, Yeast and Mould Negative in log tested Salmonella Less than 10,000 organisms per gram Negative by approved testing procedures General Requirements: The product conforms to all current USDA Regulations Governing Meat Inspection. 218